The present invention relates to the making and manufacture of a fiber reinforced heat-recoverable object by means of embedding in a matrix of polymer material, a mesh, web, plaid, etc., and being defined by strands or threads of a polymer running in a first direction, and by further strands or threads running transversely thereto and being made of material that is essentially not deformable, at least in comparison with the first mentioned polymer.
Sleeves made of a fiber reinforced material for purposes of covering a cable splice are known, e.g. through European Patent-A2 0 270 132 as well as German Patent A1 38 33 415; corresponding in parts and being included in a more extensive U.S. application by me and others, Ser. No. 379,093 filed Jul. 13, 1989, now U.S. Pat. No. 5,141,812. EP-132 suggests a mesh of shrinkable polymer threads with transversely oriented glass fibers is stretched and embedded in a polymer matrix. The reinforcement is provided here only in the direction of the glass fibers. The other application (US-allowed) suggests the use of a strand of a synthetic material upon which is wound a non-extensible thread, e.g. a glass fiber. Transverse to these strands run glass fibers and the entire arrangement is embedded in a polymer matrix.
In order to render the latter matrix as a whole shrinkable/recoverable, it is necessary to crosslink the matrix and stretch the object in the direction of the strands that carry the glass fiber coiling. During stretching the helical coiling is axially extended even though the thread of which the coil is made is by itself not stretchable. This configuration provides a two-dimensional reinforcement, that is, reinforcement that is effective in two transverse directions and thus in any direction in a plane.